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Nitrosamines are chemical compounds of the chemical structure R₁N(-R₂)-N=O, some of which are carcinogenic.

Contents 1 Occurrence in food 2 Occurrence in other consumer products 3 Cancer 4 Uses 5 Examples of nitrosamines 5.1 Tobacco-specific nitrosamines 5.2 Other nitrosamines 6 References 7 See also 8 External links

Occurrence in food

Nitrosamines are produced from nitrites and secondary amines, which often occur in the form of proteins. Their formation can occur only under certain conditions, including strongly acidic conditions such as that of the human stomach. High temperatures, as in frying, can also enhance the formation of nitrosamines. These cooking styles may be responsible for thousands of cases of colon cancer per year across the world.^{citation needed}

Under acidic conditions the nitrite forms nitrous acid (HNO₂), which is protonated and splits into the nitrosonium cation N=O⁺ and water: H₂NO₂⁺ = H₂O + NO⁺. The nitrosonium cation then reacts with an amine to produce nitrosamine.^{citation needed}

Nitrosamines are found in many foodstuffs, especially beer, fish, and fish byproducts, and also in meat and cheese products preserved with nitrite pickling salt. The U.S. government established limits on the amount of nitrites used in meat products in order to decrease cancer risk in the population. There are also rules about adding ascorbic acid or related compounds to meat, because they inhibit nitrosamine formation.^{citation needed}

Occurrence in other consumer products

Nitrosamines can be found in tobacco smoke and latex products. A test of party balloons and condoms indicated that many of them release small amounts of nitrosamines.^[1] However, nitrosamines from condoms are not expected to be of toxicological significance.^[1]

Cancer

Nitrosamines can cause cancers in a wide variety of animal species, a feature that suggests that they may also be carcinogenic in humans. Epidemiological data supports a positive association between nitrite and nitrosamine intake and gastric cancer, between meat and processed meat intake and gastric cancer and oesophageal cancer, but the studies are inconclusive.^[2]

Uses

This section does not cite any references or sources. Please help improve this section by adding citations to reliable sources. Unverifiable material may be challenged and removed. (March 2007)

• Rubber products
• Pesticides
• Certain cosmetics

Examples of nitrosamines

Tobacco-specific nitrosamines

Main article: Tobacco-specific nitrosamines

• N-Nitrosonornicotine (NNN)
• NNK
• NNAL
• NAT
• NAB
• iso-NNAL
• iso-NNAC

Other nitrosamines

• NDEA
• NDMA

References

This article needs additional citations for verification. Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (February 2008)

1. ^ Proksch E. Toxicological evaluation of nitrosamines in condoms. Int J Hyg Environ Health. 2001 Nov;204(2-3):103-10. PubMed
2. ^ Jakszyn P, Gonzalez CA. Nitrosamine and related food intake and gastric and oesophageal cancer risk: a systematic review of the epidemiological evidence. World J Gastroenterol. 2006 Jul 21;12(27):4296-303. PubMed

See also

• Nitroamine (without the 's'), compounds of the formula R₂N-NO₂.
• Nitroso, compounds of the formula R-NO

External links

• Oregon State University, Linus Pauling Institute article on Nitrosamines and cancer, including info on history of meat laws
• Risk factors in Pancreatic Cancer

Wikipedia content modification information:

• This page was last modified on 17 September 2008, at 06:41.

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